1. Field of the Invention
This invention relates to a fuel and method of preparing the economical fuel composition. More particularly, this invention relates to a method of preparing a totally combustible admixture of coal in hydrocarbon to extend the life of petroliferous deposits, and the fuel, per se.
2. Description of the Prior Art
In my earlier file and co-pending application Ser. No. 615,697, now U.S. Pat. No. 4,045,092 entitled "Fuel Composition and Method of Manufacture", filed Sept. 22, 1975, there was delineated the need for obtaining economical power, yet balancing the ecological considerations so as to achieve an over all improvement for our environment, reduce pollution and the like. Also in my co-pending application Ser. No. 688,467 now U.S. Pat. No. 4,030,893 entitled "Method of Preparing Low-Sulfur, Low-Ash Fuel", filed May 20, 1976, there was further delineated the problems of the so-called "energy shortage"; evidenced by curtailment of deliveries and then only at higher prices, of natural gas, gasoline and other petroleum products. The descriptive matter of application Ser. Nos. 615,697 now U.S. Pat. No. 4,045,092 and 688,467now U.S. Pat. No. 4,030,893 are incorporated herein by reference for details that are omitted herefrom.
An excellent discussion of the conventional sources of power and their shortcomings is contained in an article "Hydrogen: It's Future in the Nation's Energy Economy" W. E. Winsche, K. C. Hoffman, and F. J. Salzano, SCIENCE, June 29, 1973, Volume 180, Number 4093. Therein, the authors delineate the projected needs for large scale economical sources of energy such as that derived from nuclear fission, solar or geothermal sources. In that article, the authors point out the disadvantages of several conventional sources of power and extol the virtues of hydrogen as a potential future source, since it is non polluting.
In my hereinbefore referenced application Ser. No. 615,697, now U.S. Pat. No. 4,045,092 the advantages of employing methanol, instead of hydrogen, to extend the world's energy sources is delineated and claimed, particularly when employed in conjunction with a widely available substitite for petroliferous fuels; namely, coal. This bodes to be an excellent source for the future, once enough methanol is synthesized to be readily available. In the near term, however, it is desirable to employ the coal to extend the useful life of the petroliferous reservoirs. In my hereinbefore referenced application Ser. No. 688,467, now U.S. Pat. No. 4,030,893 there was delineated a method of producing a coal that had low sulfur content and low ash-producing materials so as to reduce pollution.
As noted in these hereinbefore referenced application Ser. Nos. 615,697 now U.S. Pat. No. 4,045,092 and 688,467, now Pat. No. 4,030,893 there has been tried a large variety of attempts to solve the transportation problem. Of course, the conventional technology of transporting the coal by freight, such as rail car and the like, is known. Attempts have been made to transport it by hydraulic transport, employing coal-water slurry. This has not been satisfactory because of the difficulties of pumping without settling, the difficulties in sustaining combustion with the water present and the large amount of heat that must be supplied to vaporize the water with its high heat capacity and high enthalpy requirements. In my hereinbefore referenced application Ser. No. 615,697, the use of shear thinning slurries of specifically sized and shaped particles of coal in alcohol containing 1-4 carbon atoms, inclusive, or mixtures thereof, has been delineated. There has also been delineated in a couple of patents the use of coal in hydrocarbons, such as the normally gaseous hydrocarbons that are liquified under pressure. One of the difficulties of employing the slurries of coal in hydrocarbon has been the tendency of the particulate coal to fall out of the slurry and pile up in pipe elbows, storage tanks, and the like. This has resulted in plugging of pipelines, difficulty stirable bottom sediments in storage tanks or other quiesent areas, and the like.
Thus, though this art has become crowded, it can be seen that the prior art has not been totally satisfactory in providing an interim solution for extending the life of petroliferous reservoirs by using coal in making a totally combustible slurry that did not suffer from the difficulties of the prior art and have particles of coal settle out, with the resulting problems.
Specifically the prior art has not provided admixtures that had the following features.
1. It is desirable that the admixture of coal with the hydrocarbon provide a stable suspension that can be pumped without the coal particles settling out during the hydraulic transportation.
2. It is desirable that the admixture of coal in hydrocarbon form a stable suspension in which the coal particles are maintained in a substantially uniform dispersion with only mild turbulence so as to be readily put into a uniform state by mild mixing in storage or maintained in a substantially uniform admixture by flow through a pipeline.
3. It is particularly desirable in specific embodiments that the admixture of coal in hydrocarbon form a shear thinning suspensoid that can be pumped through pipelines with a lower apparent viscosity than its at rest viscosity so as to allow transportation with lowered horse-power requirements.